Unanticipated Events
Hal Macomber posted a reference to Johanna Rothman's post on Unanticipated Events. I mentioned one approach to probabilistic planning in a previous post. Ken Flowers Risk Metrics is a pretty good start on the topic.
Johanna's approach brings up some issues with managing risk in project work...
- "The further out the dates, less you know" is VERY dependent on the context. It is common to have much of the variability of a project be "in the middle," where the system integration processes are coming together. As these activities pass, the variability of the later dates becomes less (better estimates once we get all the parts moving in the right direction).
- Variability in any estimating process is non-linear, asymmetric and combinatorial - non-linear dependencies abound
Risk Buy Down Processes
Any schedule that does not have both programmatic risk reduction and technical risk reduction is going to result in disappointment for the participants.
- Programmatic risk reduction - buffers, margin, alternative paths (alternate critical paths), and other "tricks of the trade" are needed to address this kind of risk
- Technical risk reduction - usually addressed by risk reduction engineering processes. Prototypes, risk buy down testing, mock ups, simulations, and all sorts of ways to produce a working article without producing a production article
Unanticipated Events
Yes the comet can hit the building, your can twist your ankle, the vendor can go out of business. These are known unknowns. There are several places to look for the approaches to this type of risk:
- "A Framework for Understanding Uncertainty and Its Mitigation and Exploitation in Complex Systems," Daniel Hastings and Hugh McManus, 2004 Systems Engineering Symposium.
- "Sources of Schedule Risk in Complex Systems Development," Tyson Brown, INCOSE Systems Engineering Journal, 1999. (Sorry membership required)
But more importantly is to understand the concept of "Normal Accident Theory." Having come from an environment (www.rfets.gov) where having an accident was simply not allowed - in fact was against the rules, inverting the concept of "planning" for success into "planning for unanticipated outcomes," opened my eyes to how high-risk, high-reward projects do this.
While the suggestion may be that unanticipated risk can be disruptive, the planning processes of large complex projects MUST deal with them as a normal course.
One of the best papers in recent times on the topic of risk is "Managing Project Uncertainty: From Variation to Chaos."
